Messages in this thread Patch in this message | | | From | Nicholas Mc Guire <> | Subject | [PATCH V2] clk: ux500: add range to usleep_range | Date | Thu, 11 Apr 2019 13:04:11 +0200 |
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Providing a range for usleep_range() allows the hrtimer subsystem to coalesce timers - the delay is runtime configurable so a factor 2 is taken to provide the range. With the expected range for enable_delay_us being milliseconds, the range should lie in the 250us range which is sufficient for hrtimer optimization.
Signed-off-by: Nicholas Mc Guire <hofrat@opentech.at> ---
Problem located with an experimental coccinelle script V2: As clarified by Ulf Hansson <ulf.hansson@linaro.org> the delays here are typically in the millisecond range - so as proposed replace the factor 2 by a 25% increase of max.
Patch was compile tested with: u8500_defconfig (implies COMMON_CLK=y) (with some unrelated sparse warnings about not implemented system calls) Patch is against 5.1-rc4 (localversion-next is next=20190410)
drivers/clk/ux500/clk-sysctrl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/ux500/clk-sysctrl.c b/drivers/clk/ux500/clk-sysctrl.c index 7c0403b..698306f 100644 --- a/drivers/clk/ux500/clk-sysctrl.c +++ b/drivers/clk/ux500/clk-sysctrl.c @@ -42,7 +42,8 @@ static int clk_sysctrl_prepare(struct clk_hw *hw) clk->reg_bits[0]); if (!ret && clk->enable_delay_us) - usleep_range(clk->enable_delay_us, clk->enable_delay_us); + usleep_range(clk->enable_delay_us, clk->enable_delay_us + + (clk->enable_delay_us >> 2)); return ret; } -- 2.1.4
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